Sound-box.



- WITNESSES L. F. DO UGLASS. SOUND BOX. APPLICATION FILED JUNE 5, 1909.

1,01 7,041 Patented Feb. 13, 1912.

LEON F, DGUGLASS, OF SAN RAFAEL, CALIFORNIA, ASSIG-NOR 'I'G VICTOR TALKING MACHINE COMPANY, A. CORPORATION OF NEW JERSEY.

SOUND-BOX.

inmost.

Specification of Letters Patent.

Patented n t. is, rare.

Application filed June 5, 1909. Serial No. 580,358.

mounting for a stylus bar; and to provide other improvements as will appear hereinafter.

. In the drawings, Figure 1 is a front elevation of a sound box constructed in-accordance with this invention; Fig. 2 a bottom plan view of the same; Fig. 3 a front eleva- 'tion of a modified form of this invention;

and Fig. 4- a bottom plan view corresponding to Fig. 3.

Referring to the drawings, one embodimentof this invention comprises the, usual sound box casing l, carrying mounted therein the usual diaphragm 2. A stylus bar 3 having its inner end 4 connected to the central portion of the diaphragm by any suitable means, extends radially outwardly over the front of the box.

The outer end of the stylus bar, beyond the periphery of thesound box casing, is preferably oft-set rearwardly and then projects radially outwardly and the outerend 5 of the stylus bar is provided with the usual socket for holding the stylus 6, and with the usual set screw 7 for holding the stylus in place,-the longitudinal axis of the stylus socket and stylus being preferably substantially in the plane of the diaphragm. For mounting the stylus bar to oscillate with respect to the sound box casing, the bar is provided with a transverse tubular portion 10 rigidly secured to the inside of the offset portion of the bar. Rigidly secured within this transverse tubular portion of the bar and normally projecting axially in opposite directions therefrom, is a torsional resilient rod or support 11, forming spaced torsional members for supporting the stylus bar.

For supporting the torsional rod 11, the sound box casing 1 is provided with a pair of spaced lugs 12, which are rigidly secured to-the under side of the casing and project radially therefrom, the lugs being arranged in .close proximity, to the ends of the transverse tubular portion-1O of the stylus bar and upon opposite sides of the bar. Each lug is provided upoin/its end adjacent the stylus bar, with an outwardly projecting transverse rib or boss 13, which is recessed centrally as at 14 to form abearing for the torsonial bar 11, and these bearings are axially substantially in the plane of thediaphragm 2 of the sound box.

For holding the torsional support 11 of the stylus bar upon its bearings 14, the ends of the support or bar 11 are looped to form eyes 15, which are preferably oblong in.

shape, the long diameters of the eyes extending longitudinally of the torsional bar. Extending slidably through each of these eyes is a threaded stud 16, which is rigid with the adjacent lug 12, upon the sound box casing, and extends preferably radially from the sound box, the stud being of substantially the same diameter as the short diameter of the eye. Upon the outer end of each of these studs and outside of the corresponding loop 15 of the torsional stylus bar support is threaded a thumb nut 17, the'outer surface of which is preferably knurled for convenience of operation. These nuts are adjusted to apply transverse pressures to the ends of the torsional support 11 to. flex the ends inwardly and to place the torsional support under any suitable stress, to hold the support upon its.

bearings, and to hold the ends of the sup port against rotation. Wit-h this construction in mind, it is evident that a stylus bar thus mounted is free to oscillate upon a substantially fixed axis, substantially in the plane of the diaphragm, but is restrained in its oscillation by the torsional action of its support, which may be varied by adjusting the thumb nuts to suit various'conditions, and by reason of the loops '15 being elongated, 'as best shown in Fig. 2, said torsional support may be adjusted to vary its torsional effect, without affecting its tensional constant.

A modified form of this invention, shown in Figs. 3 and 4', is similar to the form just ydescribed, except that the stylus bar is of slightly different form, the transverse tubu lar portion 10 heretofore described, being omitted, and the torsional support i1 being, rigidly secured in a transverse groove 20, upon the inner surface of the ofi-set portion 40 a mounting therefor comprising a- ,t orsional of the bar, by being soldered or brazed therein or otherwise secured in place. The outer ends of the torsional support 11 in this modified form are-provided with substantially circular eyes 21, instead of the oblong eyes heretofore described, and the threaded studs 22 engaging in these eyes project in substantially parallel directions from the sound box casing, instead of diverging radially asv 1n the previous form. In this form of invention, when the nuts 26 are threaded toward the sound box casing, the torsional support 11 is slightly fiexed'to hold the support upon its bearing 14 and to hold the ends of the support against rotation.

Although only two or" the various forms in which this invention may be embodied have been illustrated, the invention is not limited to the constructions shown as various other forms might also be used in embodying this invention without departing from the spirit of the invention or the scope of the appended claims.

Having thusfully described this invention, I claim and desire to protect by Letters Patent of the United States:

1. The combination with a stylus bar, of a mounting therefor compris'in a torsional member, means arranged to sional member, withoutefi'ecting a tensional strain on said torsional member, and means to prevent relative twisting oft-he opposite ends of said torsional member.

2. The combination with a stylus bar, of a mounting therefor comprising a torsional member rigidly secured to said bar, and

means arranged to flex said torsional memher by bowing from its connection with said bar, without tending to shift said bar.

3. The combination with a stylus bar, of

resilient member rigidly secured to said bar, means arranged to flex said torsional member, to vary the torsional coeflicient, and means arranged to prevent a tensional strain of said resilient member.

t. The combination witha stylus bar, of

a mounting therefor comprising a torsional rod rigidly connected to said stylus bar, and

exten ing transversely thereof, and means adjustable to fiex said rod by bowing, to vary its torsional efiect without affecting the normal position of said bar.

5. The combination with a stylus bar, of a mounting therefor comprising a torsional spaced bearings having open grooves supporting said torsional member, and means arranged to flex said torsional member exterior to said hearings to hold the same upon said bearings.

6. The combination with a stylus bar, of a mounting therefor comprising ,a bearing, a

ex said tor torsional member connected to said bar and engaging in said bearing, and means arranged to flex said torsional member exterior to said bearing to hold the same in said bearing, and to vary its torsional efliect, independent of its tensional constant.

7. The combination with a pair of fixed bearings, of a stylus bar arranged between said bearings, a pair of torsional arms connected to said bar and supported by said bearings, the outer ends of said arms proj ecting freely outwardly from said bearings, and having loops and adjustable means extending through said loops engaging the free ends of said arms to flex the same.

8. The combination with a stylus bar, of a mounting therefor comprising a pair of spaced projections, each provided with a groove and arranged upon opposite sides of said bar, a torsional member connected to said bar and engaging in said grooves, the ends of said member being free to flex, and means engaging the free ends of said torsional member, exterior to said projections, to flex the same to hold it in said grooves.

9. The combination with a stylus bar, of a mounting therefor comprising a pair of spaced bearings upon opposite sides of said bar, a torsional resilient cylindrical member connected to said bar and engagingin said bearings, the ends of said torsional member being free to flex, and adjustable means engaging the free ends of said torsional member exterior to said hearings, to flex the same.

10. In a sound box, the combination with a casing, of a diaphragm supported thereby, a stylus bar connected to said diaphragm, a pair of bearings, torsional arms supporting said bar and engaging in said bearings, the outer ends of said arms being free to flex and having elongated loops, threaded studs projecting through said loops from-said casing, and nuts upon said studs engaging said arms to flex the same.

11. In a sound box, the combination with a casing, of a stylus bar, a pair of bearings oppositely disposed adjacent to said bar, a resilient member supporting said bar and having free elongatedly looped ends extending exterior to said bearings, and adjustable I In witness whereof I have hereunto set my hand this 28 day of May, A. D. 1909.

3 E. DOUGLASS.

-Witnesses: 1

WILLIAM J. BOYD, JAMES B. DAVIDSON.

Copies of this patent may be obtained forv five cents each, b

.Wuhington,

b y addressing the Gommissloner of Patents, 

